Industrial gas turbines have a combustion section typically formed by an annular array of combustors. Each combustor is a cylindrical chamber which receives gas and/or liquid fuel and combustion air which are combined into a combustible mixture. The air-fuel mixture burns in the combustor to generate hot, pressurized combustion gases that are applied to drive a turbine.
The combustors are generally dual mode, single stage multi-burner units. Dual mode refers to the ability of the combustor to burn gas or liquid fuels. Single stage refers to a single combustion zone defined by the cylindrical lining of each combustor.
Stabilizing a flame in a combustor assists in providing continuous combustion, efficient generation of hot combustion gases and reduced emissions from combustion. The flames of combustion tend to oscillate due to dynamic pressure fluctuations in the combustors especially during combustion transition operations to lean fuel-air mixtures. These oscillations can extinguish the flame in a combustor and fatigue the combustor.
A single stage combustor for a gas turbine may comprise an annular array of outer fuel nozzles arranged about a center axis of the combustor and a center fuel nozzle aligned with the center axis. A pressure drop across the combustor is used to split an air flow to the combustor. However, the pressure drop may result in a maldistribution of the air flow to the outer fuel nozzles.